kawasaki, zx6r

 

I've always been confused about something and I'm sure someone here can enlighten me.

Why is driveline loss always shown as a percentage instead of a set number of HP loss? Here's why it doesn't make sense to me:

Let's say a vehicle has an engine producing 200HP. Let's say that the driveline has a loss of 25% which would be about 50HP. Now, let's say that driveline can handle 400HP from the engine without changes. So now, with 400HP, the driveline loss is 100HP from the same components (trans, transfer, diff, etc). This makes no sense to me.

I can understand it a little better if the driveline has to be upgraded as well (as in the OP's situation), but still doesn't explain the percentage. Is the percentage merely a "ballpark" or "close enough" figure that is typically use without actually calculating the friction generated by the driveline components?

 

i was thinking the exact same thing....the drivetrain should absorb a specific number of horsepower and thats it? to say it absorbs like 30hp on stock truck and 180hp from and engine that puts out 680 just doesnt make any sense to me?

 

LOL....few miles...that struck me as funny. I can picture that.

 

Nice. what year? what color?

 

so to make a less % of driveline loss, you would need a bigger stall and a shift kit correct ??

 

hahaha vrooom vrooom...break.


Driveline loss, ok so say im puttin out 680 at the crank well go with the ballpark max of 27% that would be around 500 rwhp.

Basically the drivetrain takes away a range of horsepower, depending on the type/configeration of the drivetrain. so yes, if our rams have 250 hp (for my model year) that would mean if everything is brand spankin new that im gettin roughly 190 rwhp.

That percentage is a rough basis to go off of. Each drivetrain configeration would produce a different amount of hp loss. For a general sense though, all of those configurations would pull away about the same amount of hp from the engine. Which would equate to about 15 - 20%. So if your increase your engines hp, that drivetrain will still take away that percentage of hp. SOOOO, the more hp you put into your engine, the more is going to be lost by the drivetrain, respectively. So upgrade your drivetrain to help compensate that, as much as you can. But there will always be loss.

When you say "if your drive train can handle 400hp" that just means you can run a 400hp engine with that drive train and not have it break. That percentage is still going to be there because your using that engines power to push components which will eventually turn the wheels.

So in general terms, you could say that the drivetrain is taking away a range of hp depending on numerous conditions, but those loss numbers generally fall within a certain percent range. 15-20, normally! as for me with my 4x4, like Indy said my percentage is a lil higher.

 

Stout 408s even na can tear up or rip out a tranny faster than you can say "rolling burnout" Buddy dropped his trans (ripped tailshaft off, tore trans out of block pass side) doing that shortly after dyno tuning and before we could get to the track to see what she would run lol.

Seen lots of discussion about set hp losses & % of loss over the years. When talking turbo's, superchargers & intercoolers hp made or lost is generally based on the parts efficiency which will be a %.
With higher horsepower comes higher losses to friction and inertia. Friction losses are proportional to the forces applied as well as the rpms, the more force or faster the the rpms are attained, the higher the friction losses will be. (if that makes any sense lol)

 

This has good explentations, but in a sense no your still going to have driveline loss. Things like, a lighter drive shaft with stronger and more easly moved U-joints would help more.

 

man i love physics haha.